Vehicle Equipment Installation Instructions
25
Table 7-1. Troubleshooting Symptoms, Possible Causes, and Solutions
(continued)
Symptom
Possible Cause
Solution
Incorrect wiring.
Check wiring at both ends of
radio/GPS cable.
Radio/GPS cable connector (terminal
block) plugged in backwards.
Plug in terminal block correctly.
Radio/GPS cable damaged or poor
terminations.
Replace cable, redo terminations.
Radio/GPS unit failed.
Return unit to 3M for service.
Vehicle control unit failed.
Return unit to 3M for service.
RADIO LED is amber.
No power to radio.
Check voltage between violet (+) and
violet/white (–) wires. It should be
about 9.0 VDC.
Communication cable not connected.
Check cable connection at vehicle
control unit and at computer.
Unable to communicate with vehicle
control unit.
Baud rate incorrect.
Using ITS Explorer, change baud rate
under Environment options.
Name not heard yet.
Press Get Intersections Heard button
again.
Cycle power on vehicle control unit.
Intersection Name not Heard listed
instead of intersection name.
Name not assigned in intersection.
Assign an intersection name.
Unknown Error when attempting to
communicate with vehicle control
unit.
Reset vehicle control unit.
Contact 3M Technical Service for
procedure.
Table 7-2. Expected Voltages
Location/Terminal
Expected Voltage
Notes
Red to Black wires on harness
12 VDC
Check fuse.
Blue wire on harness
12 VDC
Must have 12 VDC to activate
system, check fuse.
Brown to Brown/White
Approximately 7.15 VDC
Radio power source, check for at
least 5 seconds.
Violet to Violet/White
Approximately 7.75 VDC
GPS receiver power source, check
for at least 5 seconds.
